Severe communication delays are independent of seizure burden and persist despite contemporary treatments in SCN1A+ Dravet syndrome: Insights from the ENVISION natural history study

OBJECTIVE

Dravet syndrome (DS) is a developmental and epileptic encephalopathy characterized by high seizure burden, treatment-resistant epilepsy, and developmental stagnation. Family members rate communication deficits among the most impactful disease manifestations. We evaluated seizure burden and language/communication development in children with DS.

METHODS

ENVISION was a prospective, observational study evaluating children with DS associated with SCN1A pathogenic variants (SCN1A+ DS) enrolled at age ≤5 years. Seizure burden and antiseizure medications were assessed every 3 months and communication and language every 6 months with the Bayley Scales of Infant and Toddler Development 3rd edition and the parent-reported Vineland Adaptive Behavior Scales 3rd edition. We report data from the first year of observation, including analyses stratified by age at Baseline: 0:6-2:0 years:months (Y:M; youngest), 2:1-3:6 Y:M (middle), and 3:7-5:0 Y:M (oldest).

RESULTS

Between December 2020 and March 2023, 58 children with DS enrolled at 16 sites internationally. Median follow-up was 17.5 months (range = .0-24.0), with 54 of 58 (93.1%) followed for at least 6 months and 51 of 58 (87.9%) for 12 months. Monthly countable seizure frequency (MCSF) increased with age (median [minimum-maximum] = 1.0 in the youngest [1.0-70.0] and middle [1.0-242.0] age groups and 4.5 [.0-2647.0] in the oldest age group), and remained high, despite use of currently approved antiseizure medications. Language/communication delays were observed early, and developmental stagnation occurred after age 2 years with both instruments. In predictive modeling, chronologic age was the only significant covariate of seizure frequency (effect size = .52, p = .024). MCSF, number of antiseizure medications, age at first seizure, and convulsive status epilepticus were not predictors of language/communication raw scores.

SIGNIFICANCE

In infants and young children with SCN1A+ DS, language/communication delay and stagnation were independent of seizure burden. Our findings emphasize that the optimal therapeutic window to prevent language/communication delay is before 3 years of age.

Time to Onset of Cannabidiol (CBD) Treatment Effect and Resolution of Adverse Events in Tuberous Sclerosis Complex: Post Hoc Analysis of Randomized Controlled Phase 3 Trial GWPCARE6

Objective

To estimate the timing of cannabidiol (CBD) treatment effect (seizure reduction and adverse events [AEs]) onset, we conducted a post hoc analysis of GWPCARE6 (NCT02544763), a randomized, placebo‐controlled, phase 3 trial in patients with drug‐resistant epilepsy associated with tuberous sclerosis complex (TSC).

Methods

Patients received plant‐derived pharmaceutical formulation of highly purified CBD (Epidiolex; 100 mg/ml oral solution) at 25 mg/kg/day (CBD25) or 50 mg/kg/day (CBD50) or placebo for 16 weeks (4‐week titration, 12‐week maintenance). Treatment started at 5 mg/kg/day for all groups and reached 25 mg/kg/day on Day 9 and 50 mg/kg/day on Day 29. Percentage change from baseline in TSC‐associated seizure (countable focal or generalized) count was calculated by cumulative day (i.e., including all previous days). Time to onset and resolution of AEs were evaluated.

Results

Of 224 patients, 75 were randomized to CBD25, 73 to CBD50, and 76 to placebo. Median (range) age was 11.3 (1.1–56.8) years. Patients had discontinued a median (range) of 4 (0–15) antiseizure medications and were currently taking 3 (0–5). Difference in seizure reduction between CBD and placebo emerged on Day 6 (titrated dose, 15 mg/kg/day) and became nominally significant (p < .049) by Day 10. Separation between placebo and CBD in ≥50% responder rate also emerged by Day 10. Onset of AEs occurred during the first 2 weeks of the titration period in 61% of patients (CBD25, 61%; CBD50, 67%; placebo, 54%). In patients with an AE, resolution occurred within 4 weeks of onset in 42% of placebo and 27% of CBD patients and by end of trial in 78% of placebo and 51% of CBD patients.

Significance

Onset of treatment effect occurred within 6–10 days. AEs lasted longer for CBD than placebo, but the most common (diarrhea, decreased appetite, and somnolence) resolved during the 16‐week trial in most patients.

Pharmacokinetics and Tolerability of Multiple Doses of Pharmaceutical-Grade Synthetic Cannabidiol in Pediatric Patients with Treatment-Resistant Epilepsy

BACKGROUND

Prior studies have evaluated the use of various constituents of cannabis for their anti-seizure effects. Specifically, cannabidiol, a non-psychoactive component of cannabis, has been investigated for treatment-resistant epilepsy, but more information is needed particularly on its use in a pediatric population.

OBJECTIVE

The objective of this study was to evaluate the pharmacokinetics and safety of a synthetic pharmaceutical-grade cannabidiol oral solution in pediatric patients with treatment-resistant epilepsy.

METHODS

In this open-label study, pediatric patients (aged 1 to ≤ 17 years) with treatment-resistant epilepsy received cannabidiol oral solution administered as add-on to their current antiepileptic drug regimen. Patients received a single dose (5, 10, or 20 mg/kg) on day 1 and twice-daily dosing on days 4 through 10 (10-mg/kg [cohort 1], 20-mg/kg [cohort 2], or 40-mg/kg [cohort 3] total daily dose). Serial blood samples were collected on day 1 before dosing and up to 72 h post-dose, and on day 10 before dosing and up to 24 h post-dose. Blood samples to assess trough concentrations of cannabidiol were collected on day 6 (for patients aged 12 to ≤ 17 years), day 8 (for patients aged 2 to ≤ 17 years), and day 9 (for patients aged 6 to ≤ 17 years).

RESULTS

Overall, 61 patients across three cohorts received one of three doses of cannabidiol oral solution (mean age, 7.6 years). The age composition was similar in the three cohorts. There was a trend for increased cannabidiol exposure with increased cannabidiol oral solution dosing, but overall exposure varied. Approximately 2-6 days of twice-daily dosing provided steady-state concentrations of cannabidiol. A bi-directional drug interaction occurred with cannabidiol and clobazam. Concomitant administration of clobazam with 40 mg/kg/day of cannabidiol oral solution resulted in a 2.5-fold increase in mean cannabidiol exposure. Mean plasma clobazam concentrations were 1.7- and 2.2-fold greater in patients receiving clobazam concomitantly with 40 mg/kg/day of cannabidiol oral solution compared with 10 mg/kg/day and 20 mg/kg/day. Mean plasma norclobazam values were 1.3- and 1.9-fold higher for patients taking clobazam plus 40 mg/kg/day of cannabidiol oral solution compared with the 10-mg/kg/day and 20-mg/kg/day groups. All doses were generally well tolerated, and common adverse events that occurred at > 10% were somnolence (21.3%), anemia (18.0%), and diarrhea (16.4%).

CONCLUSIONS

Inter-individual variability in systemic cannabidiol exposure after pediatric patient treatment with cannabidiol oral solution was observed but decreased with multiple doses. Short-term administration was generally safe and well tolerated.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT02324673).

The use of a prospective audit proforma to improve door-to-mask times for acute exacerbations chronic obstructive pulmonary disease (COPD) requiring non-invasive ventilation (NIV)

Non-invasive ventilation (NIV) is an evidence based management of acidotic, hypercapnic exacerbations of COPD. Previous national and international audits of clinical practice have shown variation against guideline standards with significant delays in initiating NIV. We aimed to map the clinical pathway to better understand delays and reduce the door-to-NIV time to less than 3 hours for all patients with acidotic, hypercapnic exacerbations of COPD requiring this intervention, by mandating the use of a guideline based educational management proforma.The proforma was introduced at 7 acute hospitals in North London and Essex and initiated at admission of the patient. It was used to record the clinical pathway and patient outcomes until the point of discharge or death. Data for 138 patients were collected. 48% of patients commenced NIV within 3 hours with no reduction in door-to-mask time during the study period. Delays in starting NIV were due to: time taken for review by the medical team (101 minutes) and time taken for NIV to be started once a decision had been made (49 minutes). There were significant differences in door-to-NIV decision and mask times between differing respiratory on-call systems, p < 0.05). The introduction of the proforma had no effect on door-to-mask times over the study period. Main reasons for delay were related to timely access to medical staff and to NIV equipment; however, a marked variation in practice within these hospitals was been noted, with a 9-5 respiratory on-call system associated with shorter NIV initiation times.

The biodiversity of species and their rates of extinction, distribution, and protection

Recent studies clarify where the most vulnerable species live, where and how humanity changes the planet, and how this drives extinctions. We assess key statistics about species, their distribution, and their status. Most are undescribed. Those we know best have large geographical ranges and are often common within them. Most known species have small ranges. The numbers of small-ranged species are increasing quickly, even in well-known taxa. They are geographically concentrated and are disproportionately likely to be threatened or already extinct. Current rates of extinction are about 1000 times the likely background rate of extinction. Future rates depend on many factors and are poised to increase. Although there has been rapid progress in developing protected areas, such efforts are not ecologically representative, nor do they optimally protect biodiversity.

Abstract P1-07-08: RNA based Twist1 inhibition via dendrimer complex to reduce breast cancer cell metastasis

Breast cancer remains a leading cause of cancer related deaths for women in the United States with the principal cause of mortality being metastatic disease. Mortality rates associated with metastatic breast cancer tumors are significantly elevated compared to localized disease because the most common metastatic sites (brain, bone marrow, and lungs) are difficult to target either with chemotherapy or surgical intervention. Therefore reduction of tumor cell dispersion is a key component to a reduction in mortality rates among patients with breast cancer. Epithelial-Mesenchymal Transition (EMT) is the process by which cancer cells downregulate proteins associated with cell to cell adhesion (e.g. E-cadherin) resulting in cells that are able to detach from neighboring cells, invade adjacent tissue, and eventually enter the circulatory system or lymphatics. Many breast cancers are known to commandeer the EMT process, thus allowing the cells to metastasize beyond the primary tumor. The process of EMT is tightly regulated by the transcription factor Twist1, which is often overexpressed in breast cancer. Therefore, Twist1 serves as an excellent therapeutic target whose downregulation would result in fewer metastatic cancer cells and correspondingly reduce cancer mortality. Twist1 is also a desirable target because it is almost nonexistent in adult tissues and thus its silencing would have minimal side effects, especially compared to many of the non-specific cancer treatments used today.

Our lab has elected to use an RNA-based mediated gene silencing approach to decrease the expression levels of Twist1 in a highly invasive breast cancer cell line (SUM 1315). Due to their fragile nature, siRNA molecules are often difficult to deliver at therapeutic levels either in vitro or in vivo. We have overcome these delivery and degradation limitations through the optimization and use of Poly (amidoamine) (PAMAM) dendrimers. By complexing the siRNA with the PAMAM dendrimers not only protects the RNA molecules, but also facilitates their uptake into the tumor cells. We hypothesize that suppression of the activity of Twist1 via dendrimer-delivered Twist1 siRNA will inhibit metastatic behavior of aggressive breast cancer cells. Here we demonstrate successful delivery of Alexa Fluor® 488 labeled siRNA using two different dendrimers (Generation 5 and a modified Generation 3) with transfection efficiency results exceeding those of Lipofectamine 2000 and with far less toxicity to cells. We also show up to a 90% reduction (lasting at least 7 days) in Twist1 expression using Western Blot and qPCR analysis. Along with the knock down of Twist1, here we also demonstrate a significant knockdown of EMT proteins N-Cadherin and Vimentin. Functionally, luciferase promoter assays of Twist1 targets were also reduced. Furthermore, we were able to appreciate a significant phenotypic decrease in the invasive nature of the breast cancer cells using migration/invasion assays. Taken together these results demonstrate successful knockdown of Twist1 using siRNA dendrimer complexes resulting in an altered cellular phenotype and function. These data will serve as a foundation for optimization of future in vivo experiments with both orthotopic and metastatic breast cancer models.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-07-08.

Focal cortical dysplasia is more common in boys than in girls

Genetics and environment likely contribute to the development of medically intractable epilepsy; however, in most patients the specific combination of etiologies remains unknown. Here, we undertook a multicenter retrospective cohort study of sex distribution in pediatric patients undergoing epilepsy surgery and carried out a secondary analysis of the same population subdivided by histopathologic diagnosis. In the multicenter cohort of patients with intractable epilepsy undergoing surgery regardless of etiology (n=206), 63% were boys, which is significantly more boys than expected for the general population (Fisher exact two-tailed p=0.017). Subgroup analysis found that of the 90 patients with a histopathologic diagnosis of focal cortical dysplasia, 72% were boys, giving an odds ratio (OR) of 2.5 (95% CI, 1.34 to 4.62) for male sex. None of the other etiologies had a male sex predominance. Future studies could examine the biological relevance and potential genetic and pathophysiological mechanisms of this observation.

Vagus nerve stimulation for partial and generalized epilepsy from infancy to adolescence

OBJECT

Vagus nerve stimulation (VNS) is approved by the FDA for the treatment of partial epilepsy in patients older than 12 years. Authors of the current study performed a large retrospective analysis and comparison of VNS outcomes in children with an age ≥ and < 12 years, including those with partial and generalized epilepsy.

METHODS

A retrospective review of the records of pediatric patients (age < 18 years) who had undergone primary VNS system implantation between 2001 and 2010 by a single pediatric neurosurgeon was undertaken. Considered data included demographics, epilepsy type (partial vs generalized), seizure frequency, seizure duration, postictal period duration, and antiepileptic medication use.

RESULTS

One hundred forty-six patients (49% female) were followed up for a mean of 41 months after VNS implantation. Thirty-two percent of patients had partial epilepsy and 68% had generalized epilepsy. After VNS system implantation, seizure frequency was reduced in 91% of patients, seizure duration in 50%, postictal period in 49%, and antiepileptic medication use in 75%. There was no significant difference in age, sex, or duration of follow-up according to epilepsy type. Neither was there any significant difference in seizure frequency reduction, seizure duration, postictal period, medication use, overall clinical improvement, or improvement in quality of life based on an age ≥ or < 12 years or epilepsy type.

CONCLUSIONS

Vagus nerve stimulation reduced both seizure frequency and antiepileptic medication use in the majority of pediatric patients regardless of sex, age cohort, or epilepsy type. Vagus nerve stimulation also reduced seizure duration and postictal period in approximately half of the pediatric patients. Contrary to expectation, children with partial epilepsy do not benefit from VNS at higher rates than those with generalized epilepsy.

Changes in NHS organization of care and management of hospital admissions with COPD exacerbations between the national COPD audits of 2003 and 2008

BACKGROUND

The 2003 UK Chronic Obstructive Pulmonary Disease (COPD) audit revealed wide variability between hospital units in care delivered.

AIMS

To assess whether processes of care, patient outcomes and organization of care have improved since 2003.

DESIGN

A UK national audit was performed in 2008 to survey the organization and delivery of clinical care provided to patients admitted to hospital with COPD.

METHODS

All UK acute hospital Trusts (units) were invited to participate. Each unit completed cross-sectional resource and organization questionnaires and a prospective clinical audit comprising up to 60 consecutively admitted cases of COPD exacerbation. Comparison between 2003 and 2008 includes aggregated statistics for units participating in both audit rounds.

RESULTS

A total of 192 units participated in both audit rounds (6197 admissions in 2003 and 8170 in 2008). In 2008, patients were older and of a poorer functional class. Overall mortality was unchanged but adjusting for age and performance status, inpatient mortality (P = 0.05) and 90-day mortality (P = 0.001) were both reduced in 2008. More patients were discharged under a respiratory specialist (P < 0.01), treated with non-invasive ventilation if acidotic (P < 0.001) and accepted onto early discharge schemes (P < 0.01) while median length of stay fell from 6 to 5 days (P < 0.001). Within these mean data, however, there remains considerable inter-unit variation in organization, resources and outcomes.

CONCLUSION

Overall improvements in resources and organization are accompanied by reduced mortality, shorter admissions and greater access to specialist services. There remains, however, considerable variation in the quality of secondary care provided between units.

Skull-fixated fiducial markers improve accuracy in staged frameless stereotactic epilepsy surgery in children

OBJECT

Surgery to monitor and resect epileptogenic foci may be undertaken in 2 stages, providing an opportunity to use skull-fixated fiducials implanted during the first stage to improve the accuracy of cortical resection during the second stage. This study compared the intrinsic accuracy of skin-based and skull-fixated fiducial markers in registering frameless stereotaxy during pediatric epilepsy surgery. To the authors' knowledge, these modalities of registration have not previously been directly compared in this population.

METHODS

The authors undertook a retrospective review of pediatric patients who underwent resection of epileptogenic foci in 2 stages with frameless stereotactic assistance, performed by a single surgeon at Oregon Health & Science University. For the first stage (subdural grid implantation), 9 skin fiducial markers were used to register anatomical data in a frameless stereotactic station. Intraoperatively, four 3-mm screws were placed circumferentially around the craniotomy. Postoperatively, thin-slice brain MR and CT images were obtained and fused. For the second stage, the 4 screws were used as fiducial markers to register the stereotactic anatomical data. For both stages, accuracy (difference in millimeters from zero of the manual fiducial registration compared with the computer model) was determined using navigation software. The intrinsic accuracy of these 2 methods of fiducial registration was compared using a paired Student t-test.

RESULTS

Between 2004 and 2009, 40 pediatric patients with epilepsy underwent frameless stereotactic surgical procedures. Fourteen patients who had 2-stage procedures using skin-based and skull-fixated registration with complete accuracy data were included in this retrospective review. Mean registration error was significantly lower using skull-fixated fiducials (1.35 mm, 95% CI 1.09-1.60 mm) than using skin-based fiducials (1.85 mm, 95% CI 1.56-2.13 mm; p = 0.0016).

CONCLUSIONS

A significantly higher degree of accuracy was achieved using 4 skull-fixated fiducials compared with using 9 skin-based fiducials. This simple and accurate method for registering frameless stereotactic anatomical data does not involve the potential time, expense, discomfort, and morbidity of extraoperative skull-fixated fiducial placement. The method described in this paper could also be extrapolated to other planned 2-stage cranial surgical procedures such as combined skull base approaches.

Transendoscopic intraoperative recording of gelastic seizures from a hypothalamic hamartoma

OBJECT

The differential diagnosis of hypothalamic masses in children includes hamartomas, which are associated with gelastic seizures and endocrine dysfunction. The purpose of this study was to utilize transendoscopic electroencephalography (EEG) recording at the time of tissue biopsy to further assist in diagnosis, determination of prognosis, and treatment planning.

METHODS

We present the case of an infant with gelastic seizures and a large hypothalamic mass lesion. Despite a clinical and radiographic presentation typical of hypothalamic hamartoma (HH), slight growth on serial imaging raised concern for a diagnosis of intrinsic neoplasm. Biopsy of the lesion was recommended.

RESULTS

Transventricular, endoscopic biopsy, was undertaken, with concurrent intraoperative, transendoscopic EEG recording using a standard epilepsy depth recording macroelectrode. Numerous electrographic seizures were recorded. Histopathology revealed a HH.

CONCLUSION

This is the first report of intraoperative macroelectrode recording of electrographic seizures transendoscopically from a HH. This technique may prove useful for diagnosis, prognosis and treatment planning, as well as to guide transendoscopic therapeutic interventions for HH.

A randomised trial of peer review: the UK National Chronic Obstructive Pulmonary Disease Resources and Outcomes Project

Peer review has been widely employed within the NHS to facilitate health quality improvement but has not been rigorously evaluated. This article reports the largest randomised trial of peer review ever conducted in the UK. The peer review intervention was a reciprocal supportive exercise that included clinicians, hospital management, commissioners and patients which focused on the quality of the provision of four specific evidence-based aspects of chronic obstructive pulmonary disease care. Follow up at 12 months demonstrated few quantitative differences in the number or quality of services offered in the two groups. Qualitative data in contrast suggested many benefits of peer review in most but not all intervention units and some control teams. Findings suggest peer review in this format is a positive experience for most participants but is ineffective in some situations. Its longer term benefits and cost effectiveness require further study. The generic findings of this study have potential implications for the application of peer review throughout the NHS.

Non-invasive ventilation in chronic obstructive pulmonary disease: management of acute type 2 respiratory failure

Non-invasive ventilation (NIV) in the management of acute type 2 respiratory failure in patients with chronic obstructive pulmonary disease (COPD) represents one of the major technical advances in respiratory care over the last decade. This document updates the 2002 British Thoracic Society guidance and provides a specific focus on the use of NIV in COPD patients with acute type 2 respiratory failure. While there are a variety of ventilator units available most centres now use bi-level positive airways pressure units and this guideline refers specifically to this form of ventilatory support although many of the principles encompassed are applicable to other forms of NIV. The guideline has been produced for the clinician caring for COPD patients in the emergency and ward areas of acute hospitals.

Clinician perceived good practice in end-of-life care for patients with COPD

Patients with chronic obstructive pulmonary disease (COPD) have significant end-of-life needs, but are much less likely than patients with cancer to access or receive appropriate palliative care. Little is known about the existing availability or quality of available services within the United Kingdom. We surveyed 100 NHS acute hospitals enquiring into the provision of care for patients with COPD and requesting examples of current good practice that might be used to set standards. Forty-two percent of hospitals had formal palliative care arrangements for patients with COPD, whereas 59% had plans to develop or further develop services. Analysis of qualitative data suggested four strands that highlighted good practice; teams, care pathways, service components and linkages. These data may help to inform the debate leading to the development of standards in end-of-life care for patients with COPD.

Short burst oxygen therapy after activities of daily living in the home in chronic obstructive pulmonary disease

BACKGROUND

Short burst oxygen therapy (SBOT) is widely prescribed in the UK with little evidence of benefit. A study was performed to examine whether SBOT benefits patients when undertaking normal activities at home among those who already use it.

METHODS

Twenty-two patients with chronic obstructive pulmonary disease (COPD) were included in the study. All regularly used SBOT at home and claimed that it helps them. Each patient chose two daily living activities for which they used SBOT for relief of breathlessness. Patients were then randomised to use either an air or oxygen gas cylinder. At least 15 min later the same activity was performed using the other gas cylinder. The same process was then repeated for the second chosen activity. The main endpoints were subjective and objective times to recovery, analysed for each activity separately or taking the average over the two activities. A paired statistical analysis was performed.

RESULTS

All patients used SBOT with nasal prongs after exercise. Using the average recovery time over two activities for each patient, the mean objective recovery time was 38 s lower (95% CI -81 to +5) using oxygen and the mean subjective recovery time was 34 s lower (95% CI -69 to +2). Five patients were correctly able to distinguish oxygen from air after both activities and there was a suggestion that their recovery times were shorter than those who did not correctly identify the gases (91 s vs 20 s using objective recovery times, and 80 s vs 22 s using subjective recovery times), although this was a subgroup analysis based on only five patients with non-significant results.

CONCLUSIONS

There is some evidence that SBOT shortens recovery time after activities of daily living in a selected group of patients with COPD, but the effect is small. There appears to be a subgroup of patients who may benefit to a much greater degree.

Practical experience of using directly observed procedures, mini clinical evaluation examinations, and peer observation in pre-registration house officer (FY1) trainees

This paper describes an eight month experience with three of the four main assessment tools that will be used to validate the successful completion of the FY1 placement. The practical issues around the implementation of these new tools is of great concern to all involved in the management of postgraduate training and it is hoped that this paper will contribute some of the practical elements so far unavailable from Department of Health sources.

Admissions to hospital with exacerbations of chronic obstructive pulmonary disease: Effect of age related factors and service organisation

BACKGROUND

Exacerbations of chronic obstructive pulmonary disease (COPD) have a high rate of mortality which gets worse with advancing age. It is unknown whether this is due to age related deficiencies in process of care. A study was undertaken in patients with COPD exacerbations admitted to UK hospitals to assess whether there were age related differences in the process of care that might affect outcome, and whether different models of care affected process and outcome.

METHODS

247 hospital units audited activity and outcomes (inpatient death, death within 90 days, length of stay (LOS), readmission within 90 days) for 40 consecutive COPD exacerbation admissions in autumn 2003. Logistic regression methods were used to assess relationships between process and outcome at p < 0.001.

RESULTS

7514 patients (36% aged > or = 75 years) were included. Patients aged > or = 75 years were less likely to have blood gases documented, to have FEV1 recorded, or to be given systemic corticosteroids. Those admitted under care of the elderly (CoE) physicians were less likely to enter early discharge schemes or to receive non-invasive ventilation when acidotic. Overall inpatient and 90 day mortality was 7.4% and 15.3%, respectively. Inpatient and 90 day adjusted odds mortality rates for those aged > or = 85 years (versus < or = 65 years) were 3.25 and 2.54, respectively. Mortality was unaffected by admitting physician (CoE v general v respiratory). Age predicted LOS but not readmission. Age related deficiencies in process of care did not predict inpatient or 90 day mortality, readmission, or LOS.

CONCLUSIONS

Management of COPD exacerbations varies with age in UK hospitals. Inpatient and 90 day mortality is approximately three times higher in very elderly patients with a COPD exacerbation than in younger patients. Age related deficiencies in the process of care were not associated with mortality, but it is likely that they represent poorer quality of care and patient experience. Recommended standards of care should be applied equally to elderly patients with an exacerbation of COPD.

Understanding the internet-based distance learning preferences of European respiratory specialists

We studied the learning preferences of 160 respiratory specialists from four European countries who participated in ten internet-based learning modules and answered linked survey questions. Specialists were enthusiastic for internet learning amongst all national groups and particularly wanted to access material for teaching others. The value of social interactive learning was acknowledged but British and German subjects appeared more reluctant to participate. Internet delivered distance learning is well perceived amongst respiratory specialists. There is potential for both individual and group learning that could be realized by developing Europe-wide continuing professional development communities.

Benefits of an education programme on the self-management of aerosol and airway clearance treatments for children with cystic fibrosis

Adherence to recommended aerosol medicines and airway clearance techniques (ACT) for children with cystic fibrosis (CF) requires self-management skills. A multi-centre, randomized, controlled trial was conducted to investigate the effectiveness of a self-management education programme called 'Airways' for six- to 11-year old children with CF and their caregivers. Assessments were conducted immediately before and after the intervention period, and six and 12 months after the post-intervention assessment. The pen and paper education programme was completed by the child and caregiver together at home. Participants in the intervention and control groups had similar baseline characteristics. A per-protocol analysis was conducted and for variables that changed significantly, an additional intention-to-treat analysis was performed that included data from participants in the intervention group who withdrew from the study during the intervention period. The intervention group increased the percentage of prescribed aerosols taken (P < 0.001) and this was maintained at 12-month follow-up (P < 0.001). There was no change in the percentage of prescribed ACT performed, although when the child was unwell, caregivers in the intervention group increased the frequency and/or duration of ACT (P = 0.028) in the per-protocol analysis but not in the intention-to-treat analysis. Children in the intervention group increased their knowledge of ACT (P < 0.001) which was maintained at 12-month follow-up (P < 0.001) and felt more positively about their chest treatment regimens immediately following the intervention (P = 0.017) but not at 12-month follow-up. There were no significant changes in the control group for these variables over time. No significant changes occurred in the caregivers' reports of self-management behaviours and self-efficacy in either group. The positive results suggest that 'Airways' is a valuable educational tool for primary school-aged children with CF and their caregiver.

UK National COPD Audit 2003: Impact of hospital resources and organisation of care on patient outcome following admission for acute COPD exacerbation

BACKGROUND

Acute chronic obstructive pulmonary disease (COPD) exacerbations use many hospital bed days and have a high rate of mortality. Previous audits have shown wide variability in the length of stay and mortality between units not explained by patient factors. This study aimed to explore associations between resources and organisation of care and patient outcomes.

METHODS

234 UK acute hospitals each prospectively identified 40 consecutive acute COPD admissions, documenting process of care and outcomes from a retrospective case note audit. Units also completed a resources and organisation of care proforma.

RESULTS

Data for 7529 patients were received. Inpatient mortality was 7.4% and mortality at 90 days was 15.3%; the readmission rate was 31.4%. Mean length of stay for discharged patients was 8.7 days (median 6 days). Wide variation was observed in all outcomes between hospitals. Both inpatient mortality (odds ratio (OR) 0.67, CI 0.50 to 0.90) and 90 day mortality (OR 0.75, CI 0.60 to 0.94) were associated with a staff ratio of four or more respiratory consultants per 1000 hospital beds. The length of stay was reduced in units with more respiratory consultants, better organisation of care scores, an early discharge scheme, and local COPD management guidelines.

CONCLUSIONS

Units with more respiratory consultants and better quality organised care have lower mortality and reduced length of hospital stay. This may reflect unit resource richness. Dissemination of good organisational practice and recruitment of more respiratory specialists offers the potential for improved outcomes for hospitalised COPD patients.

Is virtual bronchoscopy useful for physicians practising in a district general hospital?

BACKGROUND

Virtual bronchoscopy software is now available to district general hospitals (DGHs). There is limited information on the clinical utility of virtual bronchoscopy and whether it offers any additional information over conventional axial computed tomography in the setting of a busy DGH chest unit.

METHODS

Virtual bronchoscopy and computed tomography findings were compared in all patients who had a virtual bronchoscopy study over a 12 month period.

RESULTS

Eighteen consecutive patients had virtual bronchoscopy for a specific clinical indication over the study period. Additional information was conveyed by virtual bronchoscopy in five patients (in four patients the airways distal to an obstruction were better visualised thereby influencing decisions about airway stenting and in one patient the virtual bronchoscopy study showed an endobronchial lesion missed on computed tomography). In nine patients who were unfit for fibreoptic bronchoscopy (FOB) the radiologist was more confident in excluding an obstructive airway lesion. The main indication for performing a virtual bronchoscopy study was to rule out an obstructive airway lesion in patients who were unfit for FOB (n = 11).

CONCLUSION

Virtual bronchoscopy is feasible and useful in the management of a few selected patients in a DGH chest unit. Virtual bronchoscopy may convey additional information over computed tomography when the distal airways need to be visualised and for discrete endoluminal lesions.

Implementation of British Thoracic Society guidelines for acute exacerbation of chronic obstructive pulmonary disease: impact on quality of life

BACKGROUND

The British Thoracic Society (BTS) guidelines have not been examined collectively for their impact on chronic obstructive pulmonary disease (COPD). Whether intensive outpatient follow up of COPD patients after acute admission, using these guidelines, improved quality of life compared to the "usual practice" of primary care follow up was investigated.

METHODS

Altogether 103 patients with a new diagnosis of COPD were admitted and screened over a four year period. Seventy patients were excluded because of another dominant medical condition or a mandatory requirement for intervention. Patients were randomised to regular primary care (control group, n = 15) or chest clinic follow up (intervention group, n = 10). Spirometry, oxygen saturation, St George's Respiratory Questionnaire (SGRQ), and Short Form 36 questionnaire were measured at baseline and six months. The intervention group was reviewed at least four times in the six month period and received spirometry, ambulatory oxygen assessment, smoking cessation advice, nebuliser assessment, a steroid trial, advice about nutrition/exercise, and introduction to a patient support group.

RESULTS

There was no significant difference between baseline measurements in the two groups. There was a significant mean (SD) improvement in the SGRQ symptom score from baseline to six months in the intervention group [20.98 (20.36)] compared with the controls [0.23 (12.55)] (p = 0.004). At six months the SGRQ symptom score, impact score, and total score was significantly better in the intervention than the control group (p = 0.01, 0.02, and 0.02).

CONCLUSION

Aggressive implementation of BTS guidelines after initial hospitalisation may improve respiratory health specific quality of life scores in patients with COPD. Larger studies are needed to confirm this finding.

A prospective study of the practical issues of local involvement in national audit of COPD

RATIONALE, AIMS AND OBJECTIVES

Variation in quality of local services is of great concern to the government and public. National audit is an important means of providing data of comparative performance but is hampered at local level by poor methodology including audit design, standard setting and data collection tools. A pilot audit of the hospital care of patients admitted with acute chronic obstructive pulmonary disease (COPD) was performed in preparation for a national audit programme and was designed and supported by experts. It was hoped to overcome these barriers. We report a prospective evaluation of the practical issues involved in local participation of hospital audit of COPD care within a national framework.

METHODS

Hospitals were recruited to the study by random selection and voluntary participation. A clinical audit study was completed over an 8-week period immediately followed by a survey of clinicians and audit staff to identify positive and negative issues of participation and the process required to achieve a successful outcome.

RESULTS

Forty-one hospitals were invited to participate, 26 (63%) accepted, and four others volunteered to meet the target of 30 enrolled centres. Reasons cited for non-participation were of inadequate resources amongst either clinicians or audit departments or prior engagement in other national or local audit schemes. Following completion of the audit most (81%) participating units reported it was a useful exercise and were willing to be involved in future audits. Negative aspects of involvement included the lack of dedicated time and manpower for audit, poor information technology and inadequate systems for identifying patient diagnoses either at admission or at discharge and incomplete case note entries. Methodological issues such as study design and data collection tools were not cited as important barriers to participation.

CONCLUSION

There is local willingness to be involved in national audit of hospital care of COPD and central provision of expert design of methods and tools may reduce some audit barriers. Nevertheless, priority must be given to improving resources identified to support audit and in improving methods and systems for data capture. These issues appear to be important in most units and represent a potentially serious barrier to achieving widespread local involvement in a national audit programme of COPD care and may also apply to other national audits designed to provide comparative assessment of National Health Service services.

Evidence for a link between mortality in acute COPD and hospital type and resources

BACKGROUND

The 1997 BTS/RCP national audit of acute care of chronic obstructive pulmonary disease (COPD) found wide variations in mortality between hospitals which were only partially explained by known audit indicators of outcome. It was hypothesised that some of the unexplained variation may result from differences in hospital type, organisation and resources. This pilot study examined the hypothesis as a factor to be included in a future national audit programme.

METHODS

Thirty hospitals in England and Wales were randomly selected by geographical region and hospital type (teaching, large district general hospital (DGH), small DGH). Data on process and outcome of care (death and length of stay) were collected retrospectively at 90 days on all prospectively identified COPD admissions over an 8 week period. Each centre completed a questionnaire relating to organisation and resources available for the care of COPD patients.

RESULTS

Eleven teaching hospitals, nine large DGHs, and 10 small DGHs provided data on 1274 cases. Mortality was high (14%) with wide variation between centres (IQR 9-19%). Small DGHs had a higher mortality (17.5%) than teaching hospitals (11.9%) and large DGHs (11.2%). When corrected for confounding factors, an excess of deaths in small DGHs was still observed (OR 1.56 (CI 1.04 to 2.35)) v teaching hospitals. Analysis of resource and organisational factors suggested higher mortality was associated with fewer doctors (OR 1.5) and with fewer patients being under the care of a specialist physician (OR 1.8). Small DGHs had fewest resources.

CONCLUSION

Significant differences in mortality may exist between hospital types. The findings justify further study in a proposed national audit.

Oxygen supplementation before or after submaximal exercise in patients with chronic obstructive pulmonary disease

BACKGROUND

Evidence for improved exercise tolerance or relief of breathlessness by short term use of oxygen before or after exercise in patients with chronic obstructive pulmonary disease (COPD) is scant, and guidelines for this treatment are lacking despite widespread provision in the UK.

METHODS

The effect of oxygenation either before or after exercise on perception of breathlessness and walk distance was studied in a group of patients with moderate to severe COPD (mean forced expiratory volume in 1 second (FEV(1)) 34% of predicted, mean 6 minute walk distance on air 283 m), all of whom desaturated by at least 4% on submaximal exercise. Oxygen (28%) or air was delivered double blind and in random order, either for 5 minutes before a standard 6 minute walk test (n=34) or for 5 minutes following the end of the test (n=18). Exercise tolerance was measured as the distance achieved and breathlessness was assessed using visual analogue scales (VAS) which were scored before and after exercise and during recovery.

RESULTS

No increase in mean walk distance after oxygen (288 v 283 m) and no improvement in mean breathlessness scores (58 v 54 mm) or recovery times occurred with oxygen taken either before (177 v 184 seconds) or after exercise (182 v 151 seconds).

CONCLUSIONS

This group of patients with COPD derived no physiological or symptomatic benefit from oxygen breathed for short periods before or after submaximal exercise. Domiciliary oxygen should only be prescribed for such patients if they have shown objective evidence of benefit on exercise testing.

Results of an extended tuberculosis screening programme among sixth formers in a London school--more questions than answers

Following the death of an unvaccinated 16-year-old school student with isoniazid resistant pulmonary tuberculosis, extended screening of sixth formers took place to identify further cases of tuberculosis and to establish the need for BCG vaccination. Eight hundred and four 16-19 year olds in the school underwent Heaf testing and completed a demographics questionnaire. Forty-nine (5.5%) of these children had a positive Heaf test and were offered a chest radiograph. Four children were diagnosed with pulmonary or mediastinal tuberculosis, none linked to the index case. Fifty-four students (6.7%) with no prior BCG had a Heaf grade 0-1 reaction and were recommended for vaccination. Ninety-one percent of students were from ethnic minority groups and 29% had been born outside the UK. British Thoracic Society recommendations on the management of tuberculin positive cases of this is open to interpretation and we suggest that a more directed and aggressive approach to TB control should be considered in inner city schools with a high proportion of at risk ethnic minority students.

Clinical audit indicators of outcome following admission to hospital with acute exacerbation of chronic obstructive pulmonary disease

BACKGROUND

The 1997 BTS/RCP national audit of acute chronic obstructive pulmonary disease (COPD) in terms of process of care has previously been reported. This paper describes from the same cases the outcomes of death, readmission rates within 3 months of initial admission, and length of stay. Identification of the main pre-admission predictors of outcome may be used to control for confounding factors in population characteristics when comparing performance between units.

METHODS

Data on 74 variables were collected retrospectively using an audit proforma from patients admitted to UK hospitals with acute COPD. Important prognostic variables for the three outcome measures were identified by relative risk and logistic regression was used to place these in order of predictive value.

RESULTS

1400 admissions from 38 acute hospitals were collated. 14% of cases died within 3 months of admission with variation between hospitals of 0-50%. Poor performance status, acidosis, and the presence of leg oedema were the best significant independent predictors of death. Age above 65, poor performance status, and lowest forced expiratory volume in 1 second (FEV(1)) tertile were the best predictors of length of stay (median 8 days). 34% of patients were readmitted (range 5-65%); lowest FEV(1) tertile, previous admission, and readmission with five or more medications were the best predictors for readmission.

CONCLUSIONS

Important predictors of outcome have been identified and formal recording of these may assist in accounting for confounding patient characteristics when making comparisons between hospitals. There is still wide variation in outcome between hospitals that remains unexplained by these factors. While some of this variance may be explained by incomplete recording of data or patient factors as yet unidentified, it seems likely that deficiencies in the process of care previously identified are responsible for poor outcomes in some units.

Effects of marine reserves on adjacent fisheries

Marine reserves have been widely promoted as conservation and fishery management tools. There are robust demonstrations of conservation benefits, but fishery benefits remain controversial. We show that marine reserves in Florida (United States) and St. Lucia have enhanced adjacent fisheries. Within 5 years of creation, a network of five small reserves in St. Lucia increased adjacent catches of artisanal fishers by between 46 and 90%, depending on the type of gear the fishers used. In Florida, reserve zones in the Merritt Island National Wildlife Refuge have supplied increasing numbers of world record-sized fish to adjacent recreational fisheries since the 1970s. Our study confirms theoretical predictions that marine reserves can play a key role in supporting fisheries.

Meeting the needs of patients with limited English proficiency

Recent guidelines have been promulgated to protect the rights of patients with limited English proficiency when they receive care from health Providers. It behooves Providers to supply access to proper interpreter services to assure appropriate and efficient care. Furthermore, legal strictures that apply include issues of malpractice on the basis of lack of informed consent and the government's ability to exclude non-compliant Providers from federally funded programs including Medicare and Medicaid.

Audit of acute admissions of COPD: standards of care and management in the hospital setting

Despite publication of several management guidelines for COPD, relatively little is known about standards of care in clinical practice. Data were collected on the management of 1400 cases of acute admission with Chronic Obstructive Pulmonary Disease in 38 UK hospitals to compare clinical practice against the recommended British Thoracic Society standards. Variation in the process of care between the different centres was analysed and a comparison of the management by respiratory specialists and nonrespiratory specialists made. There were large variations between centres for many of the variables studied. A forced expiratory volume in one second measurement was found in only 53% of cases. Of the investigations recommended in the acute management arterial blood gases were performed in 79% (interhospital range 40-100%) of admissions and oxygen was formally prescribed in only 64% (range 9-94%). Of those cases with acidosis and hypercapnia 35% had no further blood gas analysis and only 13% received ventilatory support. Long-term management was also deficient with 246 cases known to be severely hypoxic on admission yet two-thirds had no confirmation that oxygen levels had returned to levels above the requirements for long-term oxygen therapy. Only 30% of current smokers had cessation advice documented. To conclude, the median standards of care observed fell below those recommended by the guidelines. The lowest levels of performance were for patients not under the respiratory specialists, but specialists also have room for improvement. The substantial variation in the process of care between hospitals is strong evidence that it is possible for other centres with poorer performance to improve their levels of care.

Provision of an electronic library at the clinical frontline: evaluation of impact on hospital medical staff

Doctors need convenient access to the latest information if they are to meet the demands of clinical governance and evidence-based medicine. Forest Healthcare NHS Trust used its intranet to provide clinical areas with direct 24-hour access to library materials.

The Holyoake Codependency Index: investigation of the factor structure and psychometric properties

The Holyoake Codependency Index is being developed to measure the extent to which a person endorses codependent beliefs and attributions. A 28-item pilot version was administered to 39 male and 268 female clients of a family counseling agency. Factor analysis, used to identify the shortest version with acceptable reliability, yielded a 13-item final version comprising three subscales (external focus, self-sacrifice, and reactivity). The subscales correspond to key themes within the literature on codependency. Scores on each subscale correlated significantly in the predicted direction with relevant measures of psychological functioning; providing initial evidence of construct validity. The 13-item scale was administered to a general community sample of 303 women and the factor structure was fully replicated. Internal consistency of the subscales ranged from .74 to .84 with the family counseling sample and from .73 to .83 with the general community sample.

A pilot Internet teaching project to support specialist medical training

Regional training programmes involving specialist medical trainees at geographically separate sites lend themselves to distance learning methods. This paper describes the setting up and early evaluation of an internet-based project designed to support regional study days across North East Thames for respiratory medicine.

MDC-L, a novel metalloprotease disintegrin cysteine-rich protein family member expressed by human lymphocytes

The metalloprotease disintegrin cysteine-rich (MDC) proteins are a recently identified family of transmembrane proteins that function in proteolytic processing of cell surface molecules and in cell adhesion. Since lymphocytes must interact with a constantly changing environment, we hypothesized that lymphocytes would express unique MDC proteins. To identify MDC proteins expressed in human lymph node, a polymerase chain reaction-based strategy combined with degenerate oligonucleotide primers was employed. We report here the identification of MDC-L (ADAM 23), a novel member of the MDC protein family. The results obtained from cDNA cloning and Northern blot analysis of mRNA isolated from various lymphoid tissues indicate that a 2.8-kilobase mRNA encoding a transmembrane form, MDC-Lm, and a 2.2-kilobase mRNA encoding a secreted form, MDC-Ls, are expressed in a tissue-specific manner. MDC-L mRNA was shown to be predominantly expressed in secondary lymphoid tissues, such as lymph node, spleen, small intestine, stomach, colon, appendix, and trachea. Furthermore, immunohistochemical staining with an anti-MDC-L antibody demonstrated that cells with typical lymphocyte morphology are responsible for expression of the MDC-L antigen in these lymphoid tissues. MDC-Lm was found to be expressed on the surface of human peripheral blood lymphocytes and transformed B- and T-lymphocyte cell lines as an 87-kDa protein. Thus, we have identified a novel lymphocyte-expressed MDC protein family member.

Clinical value and cost of a respiratory sleep-related breathing disorders screening service for snorers referred to a District General Hospital ENT department

Sleep-related breathing disorders and snoring often co-exist in the community. We hypothesized that a significant proportion of patients referred from primary care to ENT surgeons for management of snoring might have significant sleep-related breathing disorders requiring medical management. The Respiratory Medicine Department at Whipps Cross Hospital, London, U.K. screened all such referrals using sleep questionnaires, overnight oximetry and diagnostic sleep studies where necessary as recommended by the Royal College of Physicians of London. Over 38 months, 115 patients were screened, of whom 43 (38%) had clinically significant sleep-disordered breathing. One-third were established on nasal continuous positive airway pressure ventilation and the remainder were mainly offered conservative treatment. The cost of the screening service is estimated at 14,000 Pounds for the initial year. The savings to the ENT service and the possible long-term benefits to the patients identified as having sleep-disordered breathing balance this. We conclude that screening all referred snorers for sleep-disordered breathing using a simple protocol identifies a significant number requiring medical management at a relatively low cost to the service provider.

Screening child playgroup contacts of an adult with smear negative tuberculosis

A childcare assistant with smear negative, culture positive tuberculosis worked for four months with 85 children who attended playgroups for 2.5 to 5 hours each week. Eighty-two of the children completed contact tracing procedures. No evidence was found of transmission of disease to any child.

Screening patients in general practice with COPD for long-term domiciliary oxygen requirement using pulse oximetry

Epidemiological data suggest long-term oxygen therapy (LTOT) delivered by oxygen concentrators in patients with severe hypoxic chronic obstructive pulmonary disease (COPD) is under-prescribed by General Practitioners (GPs) in England and Wales. One reason for this may be the unavailability to GPs of a measure of arterial oxygenation needed to fulfil the defined prescription criteria. Provision of a non-invasive measure of oxygenation may improve detection of hypoxic subjects and increase appropriate prescribing. This study aimed to evaluate pulse oximetry in a general practice setting and to screen for severe undetected hypoxaemia fulfilling the LTOT prescription criteria in patients with COPD. All COPD patients attending surgery in two practices were screened with oximeters for hypoxaemia. Those with an oxygen saturation of < or = 92% were referred to hospital for formal arterial blood gas analysis and an oxygen concentrator assessment. GPs were asked to evaluate their experience in the ease of use and application of oximetry. The number of patients receiving oxygen by concentrator before the study was compared with the national rate and the number after the study with the estimated need suggested by epidemiological studies. Over a 12-month period a total of 114 patients were screened in the two practices with a combined list size of 15,742. Thirteen patients had saturations of < or = 92%. Two refused and 11 underwent formal arterial gas analysis. Three had PaO2 < 7.3 kPa and new prescriptions for oxygen concentrators were made in these previously unsuspected severely hypoxaemic subjects as a result. One other hypoxaemic subject was referred and found to have another treatable medical condition. The initial prevalence of concentrator prescription (0.013% CI 0.003, 0.047) was similar to the national rate (0.024%) and the prevalence observed after screening (0.031%, CI 0.013, 0.073) fell within the lower suggested prescription need of previous epidemiological data (0.02-0.10%). All practitioners found the oximeters simple to use and helpful in assisting with assessment of the severity of their patient's condition. Oximetry provides a readily usable non-invasive method of screening and when applied to all COPD patients seen in general practice can reveal those fulfilling the criteria for long term oxygen who would otherwise not be identified as needing this treatment.

A summary of fraud and abuse issues affecting clinical research programs

In an environment where the health care industry is under unprecedented scrutiny, it is important for all of those involved in the delivery of patient care and clinical research to be aware of and adhere to government grant requirements and billing practices. Fraud and abuse violations, no matter how minor they may seem, can result in substantial consequences for the grantee institutions and the investigators themselves.

The value of forced expiratory volume in 1 s in screening subjects with stable COPD for PaO2 < 7.3 kPa qualifying for long-term oxygen therapy

Guidelines on the management of chronic obstructive pulmonary disease (COPD) issued by the European Respiratory Society (ERS), British Thoracic Society (BTS), American Thoracic Society (ATS), and Department of Health for England and Wales (DoH) suggest differing values of forced expiratory volume in 1 s (FEV1) below which arterial blood gas analysis should be performed to determine the presence of severe hypoxaemia and possible long-term oxygen therapy (LTOT) requirement. This study aimed to determine the value of FEV1 at these different levels in screening for LTOT requirement defined as PaO2 < 7.3 kPa in subjects with stable COPD. Comparative measures were taken against other lung function tests of volume and diffusing capacity. A retrospective analysis of paired lung function and arterial oxygen measurements in 491 subjects was made. The positive and negative predictive values, sensitivity and specificity of FEV1 < 70% predicted (ERS), FEV1 < 50% predicted (ATS), FEV1 < 40% predicted (BTS) and FEV1 < 1.51 (DoH) were determined for fulfilling LTOT criteria (PaO2 < 7.3 kPa). The correlation between lung function variables and PaO2 was established. Logistic regression analysis was used to classify subjects with PaO2 < 7.3 kPa and PaO2 > or = 7.3 kPa. Using FEV1 to screen for LTOT requirement produced a high negative predictive value at all four suggested limits (FEV1 < 70% 100%, FEV1 < 50% 96%, FEV1 < 40% 95%, FEV1 < 1.51 97%). However, the positive predictive values were low (FEV1 < 70% 13%, FEV1 < 50% 16%, FEV1 < 40% 19%, FEV1 < 1.51 15%) as were sensitivities. No single lung function variable was a strong determinant of PaO2. FEV1 % pred (r = 0.40), FVC % pred (r = 0.34) and TLCO % pred (r = 0.27) had the strongest relationships. Logistic regression also placed FEV1 % pred and TLCO % pred as the best predictors of PaO2 < 7.3 kPa. We conclude no lung function variable correlates well with PaO2 in subjects with stable COPD. The best predictor of PaO2 < 7.3 kPa was FEV1 % pred. Whilst a low FEV1 is a poor predictor of LTOT requirement in an individual, PaO2 < 7.3 kPa is only found in subjects with a low FEV1. A high FEV1 may be used to exclude subjects from further investigation for LTOT and prevent unnecessary arterial sampling.

Connectivity and management of caribbean coral reefs

Surface current patterns were used to map dispersal routes of pelagic larvae from 18 coral reef sites in the Caribbean. The sites varied, both as sources and recipients of larvae, by an order of magnitude. It is likely that sites supplied copiously from "upstream" reef areas will be more resilient to recruitment overfishing, less susceptible to species loss, and less reliant on local management than places with little upstream reef. The mapping of connectivity patterns will enable the identification of beneficial management partnerships among nations and the design of networks of interdependent reserves.

Comparison of the efficacy of a demand oxygen delivery system with continuous low flow oxygen in subjects with stable COPD and severe oxygen desaturation on walking

BACKGROUND

Provision of ambulatory oxygen using an intermittent pulsed flow regulated by a demand oxygen delivery system (DODS) greatly increases the limited supply time of standard portable gaseous cylinders. The efficacy of such a system has not previously been studied during submaximal exercise in subjects with severe chronic obstructive pulmonary disease (COPD) in whom desaturation is likely to be great and where usage is often most appropriate.

METHODS

Fifteen subjects with severe COPD and oxygen desaturation underwent six minute walk tests performed in random order to compare the efficacy of a demand oxygen delivery system (DODS) with continuous flow oxygen. Walk distance, breathlessness, oxygen saturation, resting time, and recovery time (objective and subjective) were recorded and compared for each walk.

RESULTS

Breathing continuous oxygen compared with baseline air breathing improved mean walk distance (295 m versus 271 m) and recovery time (47 seconds versus 112 seconds), whilst the lowest recorded saturation (81% versus 74%) and time desaturated below 90% (201 seconds versus 299 seconds) were reduced. When the DODS was compared with air breathing only the walk distance changed (283 m versus 271 m). A comparison of the DODS with continuous oxygen breathing showed the DODS to be less effective at oxygenating subjects with inferior lowest saturation (78% versus 81%), time spent below 90% (284 seconds versus 201 seconds), time to objective recovery (83 seconds versus 47 seconds), and walk distance (283 m versus 295 m).

CONCLUSIONS

Neither of the delivery systems was able to prevent desaturation in these subjects. The use of continuous flow oxygen, however, was accompanied by improvements in oxygenation, walk distance, and recovery time compared with air breathing. The DODS produced only a small increase in walk distance without elevation of oxygen saturation, but was inferior to continuous flow oxygen in most of the measured variables when compared directly.

Concept mapping: an effective instructional strategy for diet therapy

Concept mapping is an instructional strategy that requires learners to identify, graphically display, and link key concepts in instructional reading material. Although proven effective in numerous disciplines as a means to promote critical thinking and self-directed learning, concept mapping has not been tested in diet therapy. The objective of this study was to implement concept mapping as a small-group, cooperative learning strategy in an upper-division diet therapy course and to evaluate student attitudes about the effect of concept mapping on knowledge, self-directed learning, problem-solving, and collaborative skills. Students in the first semester (n = 27) initially learned course material by lecture (4 weeks) followed by an integrated mapping/lecture format (12 weeks); the second semester (n = 25) used an integrated mapping lecture format for the full 16 weeks. At the end of both semesters, students completed a 10-item original survey questionnaire. Responses for first (n = 25) and second (n = 21) semesters were analyzed independently. Results indicated that a majority of students thought participation in concept mapping enhanced knowledge of diet therapy principles (n = 19 of 25; 18 of 21), self-directed learning (n = 14 of 25; 18 of 21), critical thinking (n = 21 of 25; 14 of 21), problem-solving (n = 22 of 25; 16 of 21), and collaboration (n = 24 of 25; 20 of 21) skills. When noncooperation of teammates was a factor, concept mapping was viewed as more frustrating and time consuming than lecture. This study demonstrated concept mapping as an effective learning strategy for diet therapy; it improves students' ability to engage in self-directed learning, critical thinking, collaboration, and creative problem solving. Results suggest that concept mapping is most effective when accompanied with comprehensive training, coordinated lectures, instructor guidance, and long-term practice.

The autoantibody response to Ro/SSA in cutaneous lupus erythematosus

BACKGROUND AND DESIGN

Seventeen patients with subacute cutaneous lupus erythematosus (SCLE) were compared with 15 patients with discoid lupus erythematosus (DLE) to evaluate the relationship of 60- and 52-kd Ro/SSA autoantibodies to the clinical diagnosis and to evaluate assays for anti-Ro/SSA.

RESULTS

All serum samples from patients with SCLE had precipitating anti-Ro/SSA antibodies in immunodiffusion, and all had high titer anti-60-kd Ro/SSA in enzyme-linked immunosorbent assay. Immunoblotting was inadequately sensitive for detecting anti-60-kd Ro/SSA. Fifteen patients with SCLE had anti-52-kd Ro/SSA (11 high titer, four low titer). Only one of the 15 patients with DLE had precipitating, high-titer anti-Ro/SSA. Nine other patients with DLE had low-titer anti-60-kd Ro/SSA, and four had low-titer anti-52-kd Ro-SSA. Low-titer anti-Ro/SSA did not confer an increased risk for photosensitivity in the DLE group.

CONCLUSIONS

High-titer, precipitating antibodies to Ro/SSA are typical of SCLE and unusual in DLE. Low-titer, nonprecipitating antibodies to Ro/SSA are common in DLE and could be an indication of pathogenic factors shared with SCLE. However, low titers of anti-Ro/SSA do not confer a significant risk for SCLE skin lesions. For the purpose of clinical evaluation of skin disease, immunodiffusion assays for anti-Ro/SSA are cost-effective and informative.